Prior Art
Subceilings formed from square or rectangular panels resting on horizontal bottom flanges of inverted T-bar rails are well-known; typically a framework of rails is configured with parallel main runners, suspended from above, intersecting with cross rails to form a grid pattern, usually 2'.times.2' or 2'.times.4'. In the basic functional form of such subceilings, the bottom surfaces of the rail flanges are left exposed as flat boundary strips between the edge-supported panels, as shown, for example, in U.S. Pat. No. 3,977,144 to Jahn. In a commonly-used style of inverted T-bar rail that has become dimensionally standardized, the flanges are enclosed by a tight-fitting cap defining a smooth flat bottom surface and substantially rounded edges.
It has been a long-sought objective to facilitate remodelling of existing suspended subceilings having exposed flat T-bar flange strips by the addition of simulated beams to present an open beam architectural styling effect. U.S. Pat. Nos. 2,152,418 to Olsen, 3,241,280 to Kreuzer, and 3,685,238 to Fisher et al. show hollow beams formed as a downwardly-extending part incorporated into a form of T-bar subceiling support framework. However, such beam-shaped support rails are suited to new ceilings only, since they are not retrofittable onto an existing subceiling framework and would therefore necessitate costly removal and replacement of existing support framework and suspension hardware; furthermore, the possibility of future redecorating by changing to new beams of different shape or color would be precluded.
Supporting detachable beams on suspended rails has been taught in U.S. Pat. Nos. 1,865,131 to Olsen and 3,277,624 to Conrell, however these require the use of specialized, non-standard suspended rails, and are thus incompatible with conventional inverted T-bar suspended rails.
A specialized clip for attaching imitation ceiling beams to inverted T-bar framework is taught by Lovullo et al. in U.S. Pat. No. 3,387,872; the use of such hardware fastening items is avoided in the novel fastening method of the present invention, as one of its objects.
Prior art has failed to provide satisfactory decorative beams which may be readily added onto an installed framework of commonly-used inverted T-bar rails, both for renovating existing ceilings, and for providing in new ceiling installations the potential of convenient future renovation by changing to beams of different size, shape, color or texture, without altering or disturbing the support framework.